



01158nas a2200157   4500008004100000245007300041210006900114260001500183300001100198490000800209520069800217100001800915700001100933700001900944856003700963       2015                        eng d00aTunable Spin Qubit Coupling Mediated by a Multi-Electron Quantum Dot0 aTunable Spin Qubit Coupling Mediated by a MultiElectron Quantum   c2015/06/04  a2268030 v1143 aWe present an approach for entangling electron spin qubits localized on spatially separated impurity atoms or quantum dots via a multi-electron, two-level quantum dot. The effective exchange interaction mediated by the dot can be understood as the simplest manifestation of Ruderman-Kittel-Kasuya-Yosida exchange, and can be manipulated through gate voltage control of level splittings and tunneling amplitudes within the system. This provides both a high degree of tuneability and a means for realizing high-fidelity two-qubit gates between spatially separated spins, yielding an experimentally accessible method of coupling donor electron spins in silicon via a hybrid impurity-dot system.
1 aSrinivasa, V.1 aXu, H.1 aTaylor, J., M.  uhttp://arxiv.org/abs/1312.1711v3